Going strictly by the book, you can’t carry a bottle of Coke on the Delhi Metro. The Delhi Metro Railway Rules 2002 prohibit, carriage of “Gases compressed, liquefied or dissolved under pressure”.
On a more reasonable note, the rules also prohibit carriage of anything bigger than a briefcase (60cm x 45cm x 25cm) and weighing more than 15 kg. But tell that to the man who pushes his way inside with an extra-large suitcase, or knocks your knees with a roll of electric cable.
The Metro is fast turning lawless like the Bluelines. People are defacing coaches, boarding drunk, scuffling with Metro staff, walking on tracks... Even hawkers have started making inroads into Metro stations.
The Metro’s honeymoon with Delhi is clearly over.